Effect of Erythromycin on Microbial Antagonisms: A Study in Gnotobiotic Mice Associated with a Human Fecal Flora

Abstract

The effect of erythromycin base was studied on intestinal resistance to colonization of gnotobiotic mice inoculated with a human fecal flora and challenged with six microbial strains potentially pathogenic for immunocompromised patients. Fecal concentrations of erythromycin were greater than 1,000 micrograms/g in the human donor and in mice. Total intestinal bacterial counts were not significantly different in the human donor and in the recipient mice and were not affected by erythromycin treatment. Strains of various species from the dominant flora (greater than 10(9) colony-forming units/g) and resistant to greater than 1,000 micrograms of erythromycin/ml were present before and persisted during treatment. Strains sensitive to such concentrations - particularly all enterobacteria-were eliminated. Treatment did not reduce colonization resistance against Candida albicans, Clostridium perfringens, and erythromycin-sensitive Escherichia coli. It reduced but did not eliminate some colonization resistance against Pseudomonas aeruginosa, Clostridium difficile, and erythromycin-resistant E coli.

Colonization of Gnotobiotic Mice with Human Gut Microflora at Birth Protects Against Escherichia coli Heat-Labile Enterotoxin-Mediated Abrogation of Oral Tolerance

“…To obtain mice associated with human microflora at the neonatal stage, parent GF mice were colonized with human microflora so that their offspring were naturally colonized with this microflora at birth. For colonization at the adult stage, mice were orally inoculated twice at a 24-h interval with 0.5 mL of a 10 Ϫ2 fresh human fecal homogenate prepared and kept for 24 h in an anaerobic glove box (17). Similarly, GF adult mice were colonized with a CV adult mouse fecal microflora.…”

Role of Azithromycin Against Clinical Isolates of Family Enterobacteriaceae: A Comparison of Its Minimum Inhibitory Concentration by Three Different Methods

“…[2] Erythromycin is an old antibiotic that has been used to prevent infections caused by gram -ve enteric pathogens. [3] Use of erythromycin is limited by frequent G.I side effects was carried out by the Kirby-Bauer disk diffusion method. The MIC for azithromycin was determined by agar dilution and E-test methods.…”

Rodent models to study the relationships between mammals and their bacterial inhabitants

“…HFA animals have been used to assess the effects of antibiotics on human intestinal microbiota 86,87 and the risks associated with DNA transfer from food-borne genetically modified microorganisms. 88 Colon cancer biomarkers have also been studied in HFA animals.…”